A linearizer for a non-linear transmitter and method include a gain regulator and predistorter adapted to be coupled to a non-linear transmitter in various configurations. Bounding controllers are coupled to the gain regulator and predistorter to maintain normal operation of a transmit path to prevent unstable transmitter operation.
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1. A linearizer for a non-linear transmitter, the linearizer comprising: a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a continuously adaptive predistorter to apply complex-number amplification to provide a predistortion signal using continuously adapted predistortion values as a function of the feedback for the non-linear transmitter; an adaptive predistorter controller to estimate the nonlinearity present in the adaptive loop and control the predistorter; and a predistortion bounding controller coupled to receive signals from the non-linear transmitter and separately coupled to receive signals from the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the adaptive predistorter controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively.
A system for linearizing a non-linear transmitter includes a feedback receiver that monitors the transmitter's output. A gain regulator, coupled to the transmitter, adjusts the signal gain. An adaptive loop gain controller and a loop gain bounding controller manage the gain regulator, using feedback to prevent instability by limiting the range of gain adjustments. A predistorter applies complex-number amplification based on feedback, counteracting transmitter non-linearity. An adaptive predistorter controller estimates and compensates for non-linearity, controlling the predistorter. A predistortion bounding controller, using signals from the transmitter and receiver, prevents instability by limiting predistortion and controlling predistortion updates. Saturation or overflow flags from the transmitter or receiver are used to adjust predistortion and gain.
2. The linearizer of claim 1 wherein the loop gain bounding controller limits a dynamic range of gain values for the gain regulator, the adaptive loop gain controller having a parametric output updating gain regulation values.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a continuously adaptive predistorter to apply complex-number amplification to provide a predistortion signal using continuously adapted predistortion values as a function of the feedback for the non-linear transmitter; an adaptive predistorter controller to estimate the nonlinearity present in the adaptive loop and control the predistorter; and a predistortion bounding controller coupled to receive signals from the non-linear transmitter and separately coupled to receive signals from the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the adaptive predistorter controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, includes a loop gain bounding controller which limits the dynamic range of gain values. The adaptive loop gain controller has a parametric output which updating gain regulation values.
3. The linearizer of claim 1 wherein the predistortion bounding controller modifies the predistortion values as a function of present and past values in a moving average sense in order to reduce random variations.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a continuously adaptive predistorter to apply complex-number amplification to provide a predistortion signal using continuously adapted predistortion values as a function of the feedback for the non-linear transmitter; an adaptive predistorter controller to estimate the nonlinearity present in the adaptive loop and control the predistorter; and a predistortion bounding controller coupled to receive signals from the non-linear transmitter and separately coupled to receive signals from the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the adaptive predistorter controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, includes a predistortion bounding controller which modifies predistortion values using a moving average of present and past values to reduce random variations.
4. The linearizer of claim 1 wherein the predistortion bounding controller modifies predistortion values as a function of present and past values in a moving average to reduce random variations.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a continuously adaptive predistorter to apply complex-number amplification to provide a predistortion signal using continuously adapted predistortion values as a function of the feedback for the non-linear transmitter; an adaptive predistorter controller to estimate the nonlinearity present in the adaptive loop and control the predistorter; and a predistortion bounding controller coupled to receive signals from the non-linear transmitter and separately coupled to receive signals from the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the adaptive predistorter controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, includes a predistortion bounding controller which modifies predistortion values as a function of present and past values in a moving average to reduce random variations.
5. The linearizer of claim 1 wherein the predistortion bounding controller limits an amount by which predistortion values are changed.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a continuously adaptive predistorter to apply complex-number amplification to provide a predistortion signal using continuously adapted predistortion values as a function of the feedback for the non-linear transmitter; an adaptive predistorter controller to estimate the nonlinearity present in the adaptive loop and control the predistorter; and a predistortion bounding controller coupled to receive signals from the non-linear transmitter and separately coupled to receive signals from the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the adaptive predistorter controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, includes a predistortion bounding controller which limits the amount by which predistortion values are changed.
6. The linearizer of claim 1 wherein the predistortion bounding controller stops an adaptive process or resets predistortion values to an initial or recently estimated suitable state.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a continuously adaptive predistorter to apply complex-number amplification to provide a predistortion signal using continuously adapted predistortion values as a function of the feedback for the non-linear transmitter; an adaptive predistorter controller to estimate the nonlinearity present in the adaptive loop and control the predistorter; and a predistortion bounding controller coupled to receive signals from the non-linear transmitter and separately coupled to receive signals from the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the adaptive predistorter controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, includes a predistortion bounding controller which stops the adaptive predistortion process or resets the predistortion values to initial or recently estimated suitable states.
7. A linearizer for a non-linear transmitter, the linearizer comprising: a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively.
A system for linearizing a non-linear transmitter includes a feedback receiver that monitors the transmitter's output. A gain regulator, coupled to the transmitter, adjusts the signal gain. An adaptive loop gain controller manages the gain regulator. A loop gain bounding controller monitors the transmitter output and controls the gain regulator. A predistorter compensates for transmitter non-linearity. A continuously adaptive predistortion controller adjusts the predistorter based on feedback. A predistortion bounding controller, using signals from the predistortion controller, transmitter, and receiver, prevents instability by limiting predistortion and controlling predistortion updates. Saturation or overflow flags from the transmitter or receiver are used to adjust predistortion and gain.
8. The linearizer of claim 7 wherein the gain regulator is coupled to an output of the predistorter and directly coupleable to the non-linear transmitter.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, positions the gain regulator at the output of the predistorter and directly connectable to the non-linear transmitter.
9. The linearizer of claim 7 wherein the gain regulator is adapted to be coupled to the non-linear transmitter via the adaptive predistortion controller and predistorter.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, positions the gain regulator so it can connect to the non-linear transmitter through the adaptive predistortion controller and predistorter.
10. The linearizer of claim 7 wherein the predistortion bounding controller limits a dynamic range of applied predistortion values and limits an amount by which predistortion values are changed via the predistortion controller.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, has a predistortion bounding controller that limits the range of predistortion values applied, and also limits the amount by which predistortion values can be changed through the predistortion controller.
11. The linearizer of claim 7 wherein the predistortion bounding controller modifies predistortion values as a function of present and past values in a moving average to reduce random variations.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, includes a predistortion bounding controller that uses a moving average of current and past predistortion values to reduce random variations in predistortion.
12. The linearizer of claim 7 wherein the predistortion bounding controller limits an amount by which predistortion values are changed.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, includes a predistortion bounding controller that limits the amount of change allowed in the predistortion values.
13. The linearizer of claim 7 wherein the predistortion bounding controller stops an adaptive process or resets predistortion values to an initial or recently estimated suitable state.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, has a predistortion bounding controller that stops the adaptive predistortion process or resets the predistortion values to an initial state, or a recently estimated, more suitable state.
14. The linearizer of claim 7 wherein the loop gain bounding controller limits a dynamic range of gain values for the gain regulator.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, has a loop gain bounding controller that limits the dynamic range of gain values for the gain regulator.
15. The linearizer of claim 7 wherein the loop gain bounding controller limits a gain value update or change rate.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, has a loop gain bounding controller that limits the gain value update or change rate.
16. The linearizer of claim 7 wherein the loop gain bounding controller may stop gain regulation.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, has a loop gain bounding controller that may stop the gain regulation process.
17. The linearizer of claim 7 wherein the loop gain bounding controller resets gain values to initial or recently estimated suitable values.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, has a loop gain bounding controller that resets gain values to initial values, or to recently estimated suitable values.
18. The linearizer of claim 7 and further comprising a non-linear transmitter and wherein the feedback receiver comprises a linear receiver that provides feedback to the gain regulator and adaptive predistortion controller.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, also includes a non-linear transmitter and the feedback receiver is a linear receiver which provides feedback to the gain regulator and adaptive predistortion controller.
19. The linearizer of claim 7 wherein the predistortion bounding controller is coupled to receive a power level of the input signal, a parametric control output of the adaptive predistortion controller, actual predistortion values used by the predistorter, indications of saturation or overflow of the predistorted signal in the transmitter, and indications of saturation or overflow of an output signal in a feedback receiver.
The linearizer, as described with a feedback receiver; a gain regulator continuously adapted to be coupled to a non-linear transmitter; an adaptive loop gain controller coupled to the gain regulator; a loop gain bounding controller that receives feedback from a non-linear transmitter output and is coupled to control the gain regulator; a predistorter adapted to be coupled to the non-linear transmitter; a continuously adaptive predistortion controller coupled to the predistorter using continuously adapted predistortion values as a function of the feedback; and a predistortion bounding controller separately coupled to receive signals from each of the adaptive predistortion controller, the non-linear transmitter, and the feedback receiver to prevent unstable transmitter operation by providing predistortion control signals to provide limits on the predistorter and providing adaption control signals to the predistortion bounding controller to modify updating of the predistortion values, wherein at least one of the signals from the non-linear transmitter or the signals from the feedback receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the feedback receiver, respectively, has a predistortion bounding controller which is connected to the input signal to get its power level, the adaptive predistortion controller's parametric control output, the current predistortion values used by the predistorter, and indications of saturation/overflow of both the predistorted transmitter signal and the feedback receiver output.
20. A method comprising: obtaining feedback from signals transmitted by a non-linear transmitter; predistorting an input signal for the non-linear transmitter using continuously adapted predistortion values as a function of the feedback; bounding predistortion values used to predistort the input signal as a function of signals from the non-linear transmitter and as a function of signals from a linear receiver by providing predistortion control signals to control predistorting of the input signals and providing adaption control signals to modify updating of the predistorting of the input signals, wherein at least one of the signals from the non-linear transmitter or the signals from the linear receiver comprise a flag indicating saturation or overflow of an input to the non-linear transmitter or the linear receiver, respectively; regulating gain applied to the input signal by use of continuously adapted gain regulation values and the feedback; and bounding the gain regulation values to limit loop gain as a function of adaptive loop parametric output to prevent unstable transmitter operation.
A method for linearizing a non-linear transmitter involves obtaining feedback from the transmitter's output signals and predistorting an input signal using continuously adapted predistortion values based on the feedback. The method bounds these predistortion values using signals from both the non-linear transmitter and a linear receiver, using predistortion control signals and adaption control signals to modify the predistortion. Saturation or overflow flags from either the transmitter or receiver are considered during this bounding process. Gain is regulated by continuously adapting gain regulation values based on feedback. The gain regulation values are bounded to limit loop gain, which is a function of the adaptive loop parametric output to prevent transmitter instability.
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March 30, 2007
July 30, 2013
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